Which of the following describes mortar?

Mortar is best described as a mixture of cement, sand, and water used primarily in masonry applications. This composition allows mortar to serve as an adhesive that binds bricks, stones, or other masonry units together. The combination of materials provides the necessary workability and strength needed to create durable and stable constructions. Mortar retains sufficient moisture to cure properly, which is essential for achieving the ideal bonding characteristics as it hardens.

The other descriptions do not accurately define mortar. For example, options that mention metal and polymer or bonding agents for shingles refer to entirely different materials or applications, such as adhesives or coatings, that are not directly relevant to the traditional use of mortar in masonry. Additionally, insulation materials serve a fundamentally different purpose, as they are used to improve thermal efficiency rather than binding construction materials together. Thus, recognizing mortar as a mixture of cement, sand, and water helps one understand its key role in building projects.